N1-(5-chloropyridin-2-yl)-N2-((1S,2R,4S)-4-[(dimethylamino)carbonyl]-2-{[(5-methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)carbonyl]amino}cyclohexyl)ethanediamide represented by the following formula (I) (in the present specification, also referred to as compound I):
or a pharmaceutically acceptable salt thereof, or a solvate thereof (in the present specification, compound I, a pharmaceutically acceptable salt thereof, and solvates thereof are also collectively referred to as compound I, etc.) is known to exhibit a potent inhibitory effect on activated blood coagulation factor X and be useful as a pharmaceutical drug, particularly as an activated blood coagulation factor X inhibitor and/or an agent for preventing and/or treating thrombosis or embolism (Patent Documents 1 to 9).
Compound I is a basic compound that exhibits favorable solubility in strongly acidic aqueous solutions, but reduced solubility in neutral aqueous solutions (e.g., a neutral buffer). A pharmaceutical composition containing compound I, etc., wherein the pharmaceutical composition is coated with one or two or more coating agents selected from a cellulose derivative, a polyvinyl compound, an acrylic acid derivative, and a saccharide is known as a pharmaceutical composition having improved dissolution properties in the neutral region, containing compound I, etc. as an active ingredient (Patent Document 7). Moreover, Patent Document 9 discloses that the dissolution rate of compound I, etc. from a pharmaceutical composition containing compound I, etc. is improved by adjusting the proportion of compound I, etc. in the pharmaceutical composition.